Up to now, it has been the general practice to raise and lower sceneries manually by means of cables passed through pulleys secured to suitable supports of the stage. The cables are generally passed through further pulleys up to a control station where an operator is located. Counterweights are normally attached to the other end of the cables to balance the weight of the sceneries. In a complex play, it is common to have up to fifty battens which have to be operated at some time during the play. This oftens requires the attendance of several operators, which increases the cost of labor and also takes a lot of space on the stage. The known systems are also often unsafe for the people on the stage.